Artelino is an online art auction site but it does have quite a few images and some biographies of the artists.
ARTstor is a nonprofit digital library of more than one million images in the arts, architecture, humanities, and social sciences.
CAMIO (Catalog of Art Museum Images Online) is a growing online collection documenting works of art from around the world, representing the collections of prominent museums.
Museums:
Photobucket current Japanese art images. It is a video and image hosting site so look with care.
Asia Society provides a virtual exhibition of 25 items from there collection.
Japan Society provides a vast of array of resources on Japan.
Many of the resources above were found on the ArtPromote site. It worth taking a look at.